Rapid Detection and Identification of Biological and Chemical Agents by Immunoassay, Gene Probe Assay and Enzyme Inhibition Using a Silicon-Based Biosensor


  1. Lee. W.E.
  2. Thompson, H.G.
  3. Hall, J.G.
  4. Bader, D.E.
Corporate Authors
Defence Research Establishment Suffield, Ralston ALTA (CAN)
A rapid biosensor assay procedure that utilizes biotin-streptavidin mediated filtration capture onto nitrocellulose membrane, in conjunction with a silicon-based light-addressable potentiometric sensor (LAPS) was developed for detection and identification of biological and chemical threat agents. Sandwich immunoassays, nucleic acid hybridization assays and enzyme inhibition assays are described. For immunoassays, the lower limits of detection (LOD) per 100-Mul sample were approximately 5 pg/ml for protein (Staphylococcal enterotoxin B), 2 ng/ml for virus (Newcastle disease virus), and 20 ng/ml for vegetative bacteria (Brucella melitensis). In a dual gene probe assay format, the LOD was 0.30 fmol (1.8 x E8 copies per 60-Mul) of single stranded target DNA. Enzyme inhibition assays on the LAPS using acetylcholinesterase were able to detect soman and sarin in aqueous samples at 2 and 8 pg (100 and 600 pM), respectively. The assays were easy to perform and required a total time equal to the reaction period plus about 15 min for filtering, washing and sensing. The assay format is suitable for detection of a wide range of infectious and toxic substances. New assays can be developed and optimized readily, often within 1 or 2 days.
LAP (Light Addressable Potentiometry);Biotin;Streptevidin;Nucleic acid hybridization;Gene probes;Enzyme inhibition;Gene probe assay
Report Number
DRES-SL-1999-072 — Paper
Date of publication
08 Nov 2000
Number of Pages
Hardcopy;Document Image stored on Optical Disk

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